Property owners must deal with the possibility of intrusion upon their property by animals. While an animal simply traveling across the property may not be a problem, it can create a nuisance when the intruding animal chooses to dig holes, mark its territory, or dig in trash cans, etc. One possible method of preventing animal intrusion is by erecting a fence or other barrier; however, this is often expensive and may not be aesthetically pleasing or practicable. For example, a property owner may wish to keep animals away from an ornamental garden. Raising a fence is impractical as it obscures the garden and ruins the ornamental effect. Furthermore, the property owner may not need the entire property protected. For example, a property owner may simply need to keep animals out of a trash can.
Another possible method of preventing animal intrusion is through the use of traps or poisons. However, in a residential community where an offending animal is potentially another property owner's pet, this method is unacceptable.
Various animal deterrent systems are presently available. The deterrent stimuli used in presently available animal deterrent systems are typically audible, with the primary difference being the frequency range of the deterrent. Animal deterrent systems having deterrents which are audible in the range of human hearing quickly become a nuisance for the property owner and neighbors alike. These deterrents must be loud enough to sufficiently startle and frighten the animal to be effective as a deterrent. Further, because animal deterrent systems are desired for night time protection the deterrent may be activated during the night. This is unacceptable in many residential neighborhoods where houses are in close proximity.
More common are ultrasonic deterrents which operate at frequencies above the range of human hearing. Typically, animal deterrent systems incorporating an ultrasonic deterrent utilize a single frequency deterrent. While the selected frequency is chosen to have a deterrent effect, the constant frequency can fail to get the attention of the animal. Furthermore, the use of a single frequency does not contemplate variations in the hearing capabilities of the animals, potentially limiting the effectiveness of the animal deterrent system. U.S. Pat. No. 5,724,919 issued to Boyd et al. on Mar. 10, 1998 discloses a hand-held varying-frequency ultrasonic trainer. The '919 device includes a hand-held unit from which a positive or a negative reinforcement sound is generated by pressing the corresponding button. Depressing either button results in one of two audible stimuli which varies over a frequency range. One frequency range is selected to be soothing and the other is selected to be distressing to the animal. The '919 device contains no sensing capabilities, relying upon input from the trainer before applying a reinforcement stimuli. Accordingly, the '919 device is not suited for the continuous monitoring of a particular area as it requires the constant attention of the person operating the hand-held unit to be effective.
Presently available animal deterrent systems incorporate an infrared sensor for detecting the presence of an animal having a body temperature warmer than that of the ambient atmosphere. Typically, these sensors simply react to the presence of such a body. Accordingly, should an animal enter into the range of the sensor, the deterrent will continuously sound while the animal remains within the sensor range. Because a single deterrent pulse has the required deterrent effect, the use of a continuous deterrent places an unnecessary drain on the power supply.
Finally, properly mounting the animal deterrent system in isolated, outdoor locations is crucial for maintaining protection of the desired area. One method for mounting presently available animal deterrent systems in an isolated outdoor location is a stake which can be driven into the ground, for example in a garden. The stake is typically a rounded peg which supports the sensor unit. However, animal deterrent systems incorporating a rounded peg are subject to misalignment caused by environmental factors, such as wind and rain, or incidental contact. Such misalignment often renders the animal deterrent ineffective as it is no longer oriented to "watch" the protected area. Similarly, variations in the flora and the terrain surrounding the area to be protected affect the range at which the animal deterrent system operates, requiring the sensor unit to be mounted at various heights to compensate.
Accordingly, there is a need for an animal deterrent system which incorporates an ultrasonic deterrent of varying frequency to deter animals from a specific area. Further, there is a need for an animal deterrent system which can detect the motion of an animal and initiate a single deterrent pulse periodically until the animal leaves the sensor range. Finally, there is a need for an animal deterrent system which is capable of maintaining a desired orientation when mounted in an isolated, outdoor location.
Therefore, it is an object of the present invention to provide an animal deterrent system capable of generating an ultrasonic deterrent stimulus for deterring an animal from a protected area.
It is a further object of the present invention to provide an ultrasonic deterrent which oscillates over a specified frequency range for obtaining the attention of the target animal and increasing the effectiveness of the deterrent among various animals.
A still further object of the present invention is to provide an animal deterrent system which detects an animal within the sensor range and generates a single deterrent stimulus when the detection count exceeds a specified number within a predetermined amount of time, thereby preventing false trigger of the unit.
Yet another object of the present invention is to provide an animal deterrent system which can be securely mounted in an isolated, outdoor location so as to maintain the desired orientation of the sensor unit independent of environmental conditions or incidental contact.
Another object of the present invention is to provide an animal deterrent system which can be mounted at various heights at an isolated, outdoor location to vary the range of protection and accommodate variations in flora and terrain.